The present invention relates to a detecting apparatus, a detecting system, and a detecting method for detecting a state such as of a person to be observed and, more particularly, to a technique of automatically detecting the state of a person to be observed by using an image.
There are cases such that an unexpected accident occurs in a space in a house or the like where a resident lives and the resident is injured or dead by the accident. It is known that the ratio of a drop and a fall is relatively high as the causes of those accidents. Particularly, in the case of elderly people, a drop or fall occurs also in a relatively flat place such as a living room or a hospital room. In the case of elderly people, there are many cases that an accident such as a drop or fall leads to death or a serious disorder. It is consequently important to efficiently find an abnormal situation such as a drop and promptly handle it in order to improve the living environment of elderly people. If the state of the person to be observed can be known anytime, an observer who wants to check the state of a person to be observed such as an elderly person can immediately deal with the abnormal state of the person to be observed.
Various systems for detecting an abnormal state of a person to be observed are examined. It is desirable to provide a detecting system which has an affinity to daily life of a person to be observed. For example, a system which gives consideration also to the privacy of a person to be observed while avoiding a physical burden such as attachment of a measuring device to the person to be observed as much as possible may be provided.
As a technique for promptly finding a drop or the like of an elderly person or the like, for example, there is Japanese Unexamined Patent Application Publication No. 2002-232870 (patent literature 1). According to a technique described in the patent literature 1, a detecting apparatus captures images of a person to be observed every predetermined interval and records them. The detecting apparatus calculates a motion vector for each of pixels on the basis of image data. The detecting apparatus calculates the sum of components in the gravity force direction of the motion vectors calculated for the pixels. The detecting apparatus preliminarily stores the size of a change of a motion vector in a predetermined period in the case where a person to be observed drops. The detecting apparatus compares the sum of the components in the gravity force direction of the motion vectors calculated with the threshold and, in the case where the component in the gravity force direction of the motion vector is larger than a threshold T, determines that the person to be observed drops. In the case where it is determined that the person to be observed drops, the detecting apparatus performs a process for notifying of the drop of the person to be observed. In such a manner, according to the technique described in the patent literature 1, a drop or the like of an elderly person or the like can be promptly found.